Bad Things Happen to Good People
Harold S. Kushner wrote a bad book with a brilliant title: When Bad Things Happen to Good People.
Kushner's theology is very disappointing. For him, God is just like us. He pictures God as stuck with us in the world and who therefore has no pwer to protect His children from evil. His "God" is no God at all. Cutting God down to our size is typical of the Modernists.
The simple-minded or triumphalistic view of some believers is that those who trust in God should be protected from all harm. Good people deserve good things; bad people deserve bad things. For such people, the experience that innocent people suffer and wicked people prosper often causes them to lose their "faith" in God. They have built their house on sand and it is no wonder that it collapses when the first storm strikes it.
The Book of Job was written precisely to demolish the idea that innocent suffering is inconsistent with God's goodness.
Theodicy is the branch of theology that addresses these kinds questions.
The story of the Thorn in Paul's Side teaches us that a vigorous, active, and apostolic faith cannot protect us from suffering. "When I am weak, then I am strong. God's grace is at its best in my weakness."
Jesus' death on the Cross, His resurrection from the dead, and His future Advent in Glory is God's final and definitive answer to the problem of evil. All innocent suffering will be redressed; all evil will be annihilated.